For a reliable repair, Philips suggests entering the service alignment mode, then enter the non-volatile memory editor and change the memory setting at address ADR dec to value VAL dec and store this change.
This altered value gives lower audio power at maximum volume. He found the adjustment procedure quite confusing. I suspected that, since a different aspect ratio is used in text mode, perhaps there was some geometry corruption in certain modes. Similar faults occur in the popular Vestel chassis. To assist with my diagnosis I temporarily disabled the vertical protection by lifting one end of diode D When text was now selected, the set remained on but with severe vertical distortion.
I then found that by choosing different aspect ratios, the distortion was with zoom 1 mode only. When the service mode was accessed to enter the correct vertical values and D was refitted, text could once again be viewed normally. Alas, a few hours later the identical symptoms returned. As no dry or arcing joints had been found and there was no indication of tube flashover, I ordered IC2. This is the non-volatile memory that contains the geometry values, amongst other information.
Its part No is However, the chip that arrived was a different type, with part No Although both the original and replacement parts are SMD components, the new one was physically only half the size of the original. With a little manipulation, this was easily fitted. Retuning was the only adjustment now required. After several days testing all values remained and no further problems showed. When the source of this rail was traced right back to the associated rectifier, D, the supply was very low here also.
The only component between the cathode of D and the source — pin 10 of the chopper transformer — has the reference L It was stressed and heated. A replacement restored full vertical scan but I then found that the PCB was very sensitive.
The frame jumped and closed down with slight movement or tapping almost anywhere on the chassis. The problem was traced to poor soldering on the pins of IC Reflowing this component cured all problems. I suspect the unstable drive conditions had caused IC to draw excess current via L, causing the permanent fault.
There was a vertical output fault with this modern pure flat screen set. That is, the top half of the screen was being scanned although it was non linear while the bottom half was black and appeared to be folded up giving a bright line near the screen centre. No sound or picture here. In this case the set was dead but before noticing a complete failure, the customer said the picture flickered and the width came from the side.
If the set is dead then check the BUDX line-output transistor. Check for high ESR reading or low capacity. Often, this capacitor has an increased ESR, but in most cases it will probably be open circuit. When the set is switched, on the LED is green. Sometimes sound may be present but there is no picture due to loss of backlight. Check the four capacitors in the power supply, Nos , , , All these capacitors may exhibit low capacitance.
To ensure correct operation, you should also check the capacitors on the Scaler PCB. These have references , , , and The first check is to ensure that the LAN frame output chip, IC, is not short circuited or dry-jointed. If this proves negative, check the LT input voltage on the IC.
It should be 15V, but the set I had in for repair measured only 9V. This was due to the 3. Bush WSSIL If the set is dead but there is just a slight tripping noise, this may be accompanied by a light puff of smoke.
Check whether the nF, 2kV capacitor CD18 in the line stage has gone short circuit. Its part number is VE Philips 37FD plasma — FM33 chassis If after switch on the set goes immediately into protection mode, with the LED flashing, check all the stand-up capacitors in the power supply. All of these capacitors needed to be replaced to complete the cure. Usually, this will be the case. In this case however, the set was dead and failed to start-up, but then main HT was present across the main electrolytic capacitor.
It will just not start-up. Other fault symptoms also caused IC to work incorrectly. The set would shut down when the channels were changed. The set could be dead with the LED flashing seven times. Check for dry-joints on coil L2 on the power supply PCB. Then, before switching on, make sure any surplus glue on the component side is carefully removed and resolder the doublesided print to be sure of good contact.
I have found the second and third option codes have become corrupted. To solve the problem, I replaced the transistor with circuit reference , part No located on the signal panel.
This has circuit reference part No This fault is due to thermal instability on the transistor. Upgrading the inductor provides a lasting cure. Fault — set dead. At switch on I could hear a slight tripping noise. This initially led me to the line-output stage. A meter check across the lineoutput transistor indicated a short.
Immediately jumping to conclusions, I was already thinking about the transformer. So I checked the lineoutput transistor. I disconnected the line stage and this proved that the fault was in the power supply. Checking the ht rail led me to pF, 2kV capacitor C, which was short-circuited. After replacing it, all was well. This home-cinema unit appeared to be completely dead. It employs a standby power supply on a small board at the front right. The main supply is based on a large toroidal transformer with linear regulators.
This comes from a 2SC regulator transistor, Q The device proved to be open circuit between its base and collector. I replaced this somewhat under-rated device with a chunkier MJE normal operation was restored. The external power supply checked out OK. This led to the internal power supply.
Today luck was on my side. There was a lovely dry joint on the regulator, circuit reference n After a careful reflow, all was well. Philips A10 chassis I have had a couple of these ageing sets in recently with the same symptoms, i. The RF input is perfect. To solve the problem,. Fortunately, for a change, it was a nice easy one!
Capacitor C, located right next to some hot-running diodes, had dried out, and popped its leadout bung. A replacement soon got the unit going again. If the DVD display is lost with loss of mechanical functions on the video section then this may well be due to there being no 12V supply on the video PCB.
A quick check may soon point to the 2SCY transistor Q I suggest replacing it even though it may not appear faulty. Before turning the set on though after replacing the diode, also consider replacing the PC shunt regulator Q The disc clamper is pivoted to the rear of the disc and is held in place by a plastic clip on the left hand side of the clamper.
There is a strong spring underneath the back of the clamper that provides the clamping action. Due to wear in the pivot and clip, the spring was pushing the clamper. This meant that the rotating part of the clamp was catching on the fixed part as the disc rotated. Adjacent to the clip, there was a plastic peg protruding from the chassis. This had a hole in the top. It looked as if the problem had been anticipated but the cure never implemented.
When a suitable selftapping screw and washer were fitted here, the disc was clamped perfectly and discs were played normally. It is a Dolby Pro-logic surround-sound system driving five loudspeakers. The complaint was no sound. From the indications on the displays, everything appeared to be working but the only sound was a series of random crackles from the speakers. The volume of the crackles varied as the volume control was operated, which suggested that the fault was in the signal path prior to the volume control.
There was a good signal at the input. A signal injected at the output of the sound processor, on the socket where it feeds the amplifier, gave a good output from the speakers OK, I stuck my finger on it and got a nice buzz from the speakers!
This proved that the fault was somewhere in the sound processor. I began to get a bad feeling about the DSP chip, which is a large multipin surface-mount device. A check on the output of this IC confirmed my suspicions that it was not producing an output, as the random crackles were the only signal here.
This 5V supply is derived from a 7V. The 7V supply was present on Q From here it is fed through 2. This diode had a very high forward resistance. After I had replaced it with a 1N, all was well. There was a loud Hz hum from the speakers when the unit was turned on. Usually this symptom is caused by short circuit or leaky output transistors drawing excessive current. The output transistors tested OK. There were no other measurable faults but I decided to replace the output transistors on both channels anyway.
This appeared to have cured the fault. When the amplifier was powered up it worked normally. After soak testing, however, the fault returned and I hastily turned the set off. When I turned it back on, the fault had disappeared again. After scratching my head, I decided to replace all the transistors in both channels as they are very cheap. An intermittent transistor seemed to be the most likely cause of the fault.
Again the amplifier worked normally. It continued to do so for more than a day when the fault returned. By now I was tearing my hair out, having tried heating, freezing and any other tricks I could think of. To cut a long story short, which involved substituting capacitors, diodes, etc.
After a further soak test of nearly a week the fault seemed to be cured. It has been three months since the unit was returned to the customer and I have not heard. This was caused by a suppressor capacitor and resistor combination package connected across the mains input.
With these tuners, the capacitor sometimes goes leaky and the component starts burning. Note that this is a safety component and only a class X2 part specially designed for the job should be used.
Despite trawling the internet and every catalogue I could think of, I could not find a supplier. I was contemplating fitting a toggle switch on the back when I had a sudden idea.
I got out the service manual for the Quad 33 preamp. Sure enough it was fitted with an almost identical component. A phone call to Quad produced the appropriate, but rather expensive, part. The unit was showing no signs of life. There should have been a 5V standby supply to the CPU. This supply measured low. Disconnecting various items from the supply rail proved that it was being pulled down by something on the front panel.
Further disconnection of components. With the IR receiver disconnected, the rest of the unit worked normally. I managed to find a replacement part in the Farnell catalogue, part number After fitting it and testing with the remote control, which the customer fortunately had brought in, all was well. There are two fans fitted to the rear of this amplifier. Both run off a 12V supply. The supply is switched on by either of two bi-metallic type sensors bolted to each of the two output-stage heat sinks.
Tests proved that the 12V supply was indeed present at the fan connectors above this temperature. At first I thought that both fans must be faulty, although this seemed rather unlikely. Then I realised that they had been connected with reversed polarity during manufacture and so could never have worked! Reversing the fan connections provided a cure. Initially, the customer said that the sound had gone off but that DVDs had continued to play with a good picture.
I am a bit dubious about tackling storm damaged equipment. Sometimes there can be lots of unseen damage that can take hours to put right.
The job can end up being hopelessly uneconomical repair. Everything looked as though it was going to work. However, as soon as the DVD player attempted to read a disc the whole unit would shut down. Fortunately I managed to borrow a power-supply panel from another machine which proved that the power supply was the cause of the problem. With the borrowed panel, everything now worked as expected, albeit with no sound.
A replacement got the power supply working. Now for the sound fault. The cause was located on the panel inside the sub-woofer unit and is the subject of a JVC modification. After replacing these parts and reassembling, everything worked as it should.
This can cause various symptoms, but usually there is no display and there are no functions. Often, the distinctive smell of leaking capacitors is noticeable when the cover is removed. Also, the board in the area of the capacitors — which are about half way along the right hand edge of the board looking from the front — may be corroded.
The board will need cleaning up in any case. Adjacent components should be checked for corrosion and. Another fault is no audio output although discs appear to be playing normally. Parts will probably have to be obtained via a friendly Linn dealer. A large DC voltage was measurable on the speaker output.
It was almost up to the level of the positive supply. The output transistors were OK and so were all the other components checked in the output stage. Repairing this crack cured the fault. Linn Axis Turntable This fault caused the motor to lose power. It is a synchronous motor that runs from a power supply.
Replacing the electrolytic capacitors, which tend to dry out, is a good starting point. If these are tested with an ESR meter you will find most of them are out of specification or even open circuit. I find it best to replace the lot.
Usually this will get the motor running again but I have had one or two other problems. If either is open circuit it will cause this fault. Sometimes I. In one case, most of them were cracked, which I assumed must have been caused by a lighting strike. Replacing them all cured the fault. Most of them only cost a few pence. Occasionally the motor will have one of its two windings open circuit.
In this case it will run with no load — belt not fitted — or if started by hand. I replace LCD display backlights fairly frequently, but in this case the unit was fitted with a fluorescent display. On investigating, I found that about half the many pins of the display were badly dry jointed. Resoldering all the pins restored the display and produced a happy customer.
This was because the speaker protect relay was not closing. For once, the reason for this was a nice simple one. I could find no particular issue to have caused it to fail, so I went ahead and replaced it. This restored normal operation. I opened the case and had a little poke around the standby transformer board. Ths board contains the relay for switching the main power transformer.
I was surprised to find. Once the wire had been stripped back and resoldered where it belonged, all was well. How the wire became disconnected is a mystery. Fortunately, most of the problems that these suffer from come down to one reasonably easy to get at component. In this case, the unit was intermittently dead from the front end. However, when it was wrong, no signals applied to any of its analogue, coaxial digital or optical digital inputs, were detected or processed.
Occasionally, the unit would burst into life, and continue to work normally until it was next powered down. At the front centre of the amplifier, between the two large output stage heatsinks, is another smaller one. Once the strengthener bar, which runs from front to back of the unit, has been removed you can undo its two mounting screws and gently lift it out as far as its cabling will allow.
You will need to cut some cable ties here. It is actually one of seven that run along the edge of the board. Four of these are four-pin specials types. Three of them are type.
Check the pin 2 outputs of all of these regulators, counting from their left-most pin. All seven regulators need to be unscrewed from the heatsink to get to the back of the board. When you separate the devices from the heatsink, you will probably find that no thermal grease has been used. This may be a contributory factor in the frequent failure of these devices.
Before refitting the board, I always put a smear of heatsink compound on all seven regulators. In this particular example, the failed regulator was IC which had just 2.
A replacement restored a full 5V, and normal operation of the amplifier. Like Michael commented in the January issue of Television, my heart also sinks when I see a big mixer desk walking in the door. Not so much in my case because of the bulk and. Mixer desks are invariably built such that in order to get a board out, every associated rotary and slider knob has to be first removed, then all of the fixing nuts and screws on the potentiometers, as well as those on any sockets.
Often, there may be or more knobs to come off, and a similar number of nuts to undo. A useful tip here, is to take a digital photo of the desk before you start removing knobs. The chap from the shop said that he thought it might be a power supply problem. These desks use a separate external rack-mount power supply. I have in the past had the linear regulator ICs fail, so this was my first hope.
When I checked at the output of the LM regulator for the V rail, there was indeed nothing there, although there was a good solid V going in. Unfortunately, the regulator was too hot to touch, indicating that it had gone into safety foldback, due. A quick switch to an ohms range on my meter confirmed that there was an almost dead short across the rail. When the desk was unplugged, the short went away, and the output of the regulator returned to its normal value.
This was the point at which my heart really began to sink. There are several sets of link plugs between the boards, so my next move was to disconnect the first one in line, to isolate the first main board from the other two. Again, the short went away, indicating that the problem was not on the first board.
It was at this point that I did a foolish thing. I replugged the link cable with the power still switched on, and guess what? Still no short. In fact, the whole desk now worked correctly. This means that the sudden application of fully established power to whatever part was at fault blasted the problem away.
So, have I fixed it? Short-term, certainly. Steven and Paul are at it all the time now. The other morning I awoke to find another of their beerstained notes on the mat. I felt nasty, so I ran upstairs and smacked the bedroom lights on. Her eyes opened wide, like a pair of emeralds set against a promising sky. I felt better already. Ruff, the perpetually pregnant parasite with a foghorn voice and three thick lodgers who failed to reflect much light.
I tried to raise a false smile, but my face slipped to a lop-sided leer as I started to unlock the shop door. Her three assorted brats helped by kicking it open and rushing in first.
One ran to the counter and laid into it with his boots whilst another stuffed yards of bubblegum into the mouth of a DVD recorder on display. And the third spun the battery rack so hard that its batteries shot about the shop like shells. I collected a pack of high velocity U2s on the shin as I wove and ducked my way behind the counter. Greeneyes, I noticed as I spun, was cleverly dawdling about the car, divorced from the drama. With my shins safe from further assault, I drew up the pad of job cards and was patting about for my pen as Mrs.
Ruff slammed her DVD player down onto my hand. No, I tell a lie! I tried to look suitably sad. She looked thoughtful and pursed her rubber lips.
Boyhood interests. When I was a schoolboy there was no television and my indoor interests were mainly centred on sound. I still remember the thrill I got when I encountered, on the forecourt of the local second-hand shop, an HMV table cabinet gramophone.
It was ancient then. I nodded and drifted. Three days later I asked him again. About four days after that I wandered back to have another look. Out he darted and I asked him again. The weekend came and went, and on the Tuesday I wandered there again. Presently he came out and sloped over, and as I breathed in to speak, he put his fingers over my lips. Give me Half a Crown for the gramophone and all these records! I had halfa crown! But the volume from its giant horn was too much for the room.
I tried stuffing rags down the horn, but this made the sound tinny, and one hot afternoon I halfpointed its horn through my open window. Trouble Whilst it played away, I sat beside it with my eyes closed in ecstasy. None of my school chums had a gramophone, I mused.
Poor devils! Occasionally I looked out of the window, past the horn, but was disappointed to see there was nobody about — except a miserable old fool jumping about with his fingers in his ears. Troubled with some sort of insect phobia, I concluded, as I pushed the horn right through the open window and pointed it up the street. Suddenly I spotted a distant figure on a bike, energetically peddling towards our house.
He seemed a friendly man. He was travelling at a terrific speed, and as he neared the house I saw that it was our father. And he was waving at me! For industries that require clean environments such as the food, beverage and pharmaceutical industry, an oil-free air compressor may be necessary to minimize the risk of contamination.
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Country Contact us if your Country is not listed. Barthelemy St. Croix St. Lucia St. Maarten St. Specifications subject to change without notice or obligation. Specifications guaranteed only within Amateur band. The receiver uses double-conversion superheterodyne circuitry, with a The 1st local, produced by a PLL synthesizer, yields the The 2nd local uses a The 2nd mixer and other circuits use a custom IC to convert and amplify the 2nd IF, and detect FM to obtain demodulated signals.
During transmit, the PLL synthesizer oscillates at the desired frequency directly, for amplification to obtain RF power output. The This IC contains the 2nd mixer, 2nd local oscillator, limiter amplifier, FM detector, noise amplifier, S-meter amplifier and squelch gates. After passing through a limiter amplifier, the signal is demodulated by the FM detector.
After volume adjustment by the AF power amplifier Q LAA , the audio signal is passed to the optional headphone or 8-ohm loudspeaker. PLL synthesizer IC Q LVV consists of a prescaler, reference counter, swallow counter, programmable counter, a serial data input port to set these counters based on external data, a phase comparator, and a charge pump.
The VCO output is divided by the prescaler, swallow counter and programmable counter. These two signals are compared by the phase comparator and applied to the charge pump. A voltage proportional to their phase difference is delivered to the low-pass filter circuit, then fed back to the VCO as a voltage with phase error, controlling and stabilizing the oscillating frequency.
This synthesizer also operates as a modulator during transmit. Synthesizer output is fed to the 1st mixer by diode switch D 1SS during receive, and to pri-drive amplifier Q 2SC for transmit. The reference oscillator feeds the PLL synthesizer, and is composed of crystal X The RF energy then passes through antenna switch D XB15A and a lowpass filter circuit and finally to the antenna connector.
RF output power from the final amplifier is sampled by. Generation of spurious products by the transmitter is minimized by the fundamental carrier frequency being equal to the final transmitting frequency, modulated directly in the transmit VCO. Additionally harmonic suppression is provided by a lowpass filter consisting of L, L, C, C, C, and C, resulting in more than 60 dB of harmonic suppression prior to delivery of the RF. The FTM has been carefully aligned at the factory for the specified performance at the MHz amateur band.
Realignment should therefore not be necessary except in the event of a component failure. All component replacement and service should be performed only by an authorized Vertex Standard representative, or the warranty policy may be voided.
The following test equipment and thorough familiarity with its correct use is necessary for complete realignment. Correction of problems caused by misalignment resulting from use of improper test equipment is not covered under the warranty policy.
While most steps do not require all of the equipment listed, the interactions of some adjustments may require that more complex adjustments be performed afterwards. Do not attempt to perform only a single step unless it is clearly isolated electrically from all other steps. Have all test equipment ready before beginning, and follow all of the steps in a section in the order presented. The following procedures cover the sometimes critical and tedious adjustments that are not normally required once the transceiver has left the factory.
However, if damage occurs and some parts are replaced, realignment may be required. If a sudden problem occurs during normal operation, it is likely due to component failure; realignment should not be done until after the faulty component has been replaced.
We recommend that servicing be performed only by authorized Vertex Standard service technicians who are experienced with the circuitry and fully equipped for repair and alignment. Therefore, if a fault is suspected, contact the dealer from whom the transceiver was purchased for instructions regarding repair.
Authorized Vertex Standard service technicians realign all circuits and make complete performance checks to ensure compliance with factory specifications after replacing any faulty components. Those who do undertake any of the following alignments are cautioned to proceed at their own risk.
Problems caused by unauthorized attempts at realignment are not covered by the warranty policy. Also, Vertex Standard must reserve the right to change circuits and alignment procedures in the interest of improved performance, without notifying owners.
Under no circumstances should any alignment be attempted unless the normal function and operation of the transceiver are clearly understood, the cause of the malfunction has been clearly pinpointed and any faulty components replaced, and the need for realignment determined to be absolutely necessary. Correct alignment is not possible with an antenna. After completing one step, read the following step to determine whether the same test equipment will be required.
If not, remove the test equipment except dummy load and wattmeter, if connected before proceeding. When the transceiver is brought into the shop from hot or cold air it should be allowed some time for thermal equalization with the environment before alignment.
If possible, alignments should be made with oscillator shields and circuit boards firmly affixed in place.
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