Die_Bogener
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Bad sound Penta?
- Dead mids
- misaligned refoamed Mids
- blocked mids
- scratching mids
- wrong wirement of the mids, reversed, + = – ?
- wires not marked during rework… and you have a very nice day
- there are only 5 of 8 orange wires on the mids, which one is the right one???
- dead tweeter
- burnt tweeter resistor
- dead tweeter cap
- wrong recap of the crossovers, bad material
- recap is not recap, sometimes recap is badcap… good material out, worse material in
- broken coils in the crossover…
… and we did not talk about the amp. Just the box.
New cassette loading unit online.
“VX5000 Kassetten Ladeschacht neu”
Last new part…
He would remember that…
… sticky black fingers, sticky black tools, sticky black floor, sticky black vacuum cleaner…
Nobody will forget it who has ever opened this Box of the Pandora… 😉
Check the connectors of the flap, the solder breaks…
And all other connectors. I have one Penta here for repair, it’s power connector after the rectifier is broken on the mainboard… solder defect.
A worm drive will always yam the loading mechanism. It is impossible to turn it from outside.
Or it will break by forcing the cassette into the VX. What happened…
This is the trigger to load a cassette… moving the cassette 15mm inside the loading mechanism will trigger the switch on the drive board…
There is the 12V power regulator. It becomes really hot, even if the VX is ok and in standby. 60 degrees are quite normal, consuming 20W in standby… that’s a lot…
That’s why this VX had only a lifetime of some hundred hours. I had some VX5000 not surviving the first year in 1988…
The VX can be modified to save power. But this is a complete and very radical modification. A modified VX5000 consumes less than 10W, the VX7000 can be less 5W…
But… you can remove the analog tuner as a first step. There is no analog radio station on this planet any more… so, it’s a waste of space and electricity… and inside the tuner are also defect caps … 😉
Do you see the missing tuner? It is not necessary at all… just remove it. This works for the VX5000/5500/7000… less is more 🙂
Remove the tuner… or repair it. And when it is repaired, why put it in again? It’s a useless part…
The metall box is the head amp.
Important for noisy pictures and missing sound. It decodes Picture and Sound from the tape… just tape playback and record.
If sound is bad even from AV decoder input, it’s something else defect, not the head amp. (VTAPE – Shift 7 for input….). Worth testing…
But… the front panel has 2 linear potis for recording. And 2x mini 1uF or 10uF caps exactly for recording left/right next to the potis…
As i said, the VX5000 has a lot of caps inside…
Have you made the digital unit already? Can you activate this unit? MX5000 or MX5500?
There are a lot of them in a very special size of RM 2,5mm … very special and really very hard to get in this size. RM2,5 is usually no problem, it’s the mechanical size of them, some are bipolar… that’s why they are red now 😉
All video signal runs through this unit, even if no digital effect is used. Just pass through…
The small board above is the text overlay for the menu. Already done? RGB working? The size is there more than critical, every millimeter counts… i use meanwhile SMD R7y bipolar caps for the RGB unit…
Different sound level:
- during playback?
- during input from scart decoder?
- after recording?
- from tuner?
- old and checked tapes?
- 2-channel sound L1 and L2 and Linear?
- Head amp caps replaced? There is a sound track amp… box behind the head…
What about the bigger cap for the Dolby chip right in the middle? Not dead as usuall?
This is the board for sound playback.
But… the lower mainboard is still defect. Why not done?
All these caps are dead and will destroy all and everything with acid. It’s the complete drive control…
The tuner board has a hinge to open it 90 degrees… and the hinge has a function to remove the tuner board… turn and push/pull axial … no need to open bolts on the hinge.
The tuner can be removed and the master is still working without the tuner, so you can test it on your desk.
The black bottom plate is easy to remove… 4+3 bolts. Then you have access to all other boards from both sides without removing them out of the cabinet.
The defect buttons: check the button on the board. There can be oxyd inside the switch, especially when there was smoking nicotin. Then you need the switches.
Sometimes the connector ob the display board to the cpu board makes problems. I have also seen keramic caps break near the connector because there is sooooo much solder, there is a filter cap row and the thermic expansion makes them crack.
There is a small board on the right side vertical on the lower mainboard. This makes the playback sound.
Never (!!!) change B&O adjustments, it will become only worse.
…and yes, it’s a cap problem.
VX5000/5500 and 7000 have the same loading gear. The 7000 has a better material, usually stronger.
Balance max to the right and no sound on left?
Quite normal. Everything ok.
Just center the balance.
Working without the lithium cell is a very bad idea.
7-segment and Led’s for the source are done with the same chip… and the relais.
There is a LED driver chip MM5450 on the display board. If there is a problem with overload of a segment… the chip has internal led driver resistors… it will have problems to activate the defekt segment causing a power failure of the display/cpu… that’s the flicker.
Try the amp without speakers to activate from 0 to 64 to check all these segments. Usually there will be a “8” problem… and a problem with the source led.
It can be the chip or the power supply itself.
Replacing the chip is very skilled work and the chip is hard to get.
Usually some caps in the power supply are the cause…
It is the internal resistor of these blue Philips/BC caps. They are NOT LOW ESR…
… and the player hates LOW ESR for C2103.
Replace all and everything whatever you want, but C2103 must be a blue Philips.
And check for cracks on the connectors.
Original function of the signal board of a VX7000… repaired, restored, working, 100% function like it was 1989…
Modified board, repaired, 100% functional with satellite unit using the auxiliary port … and 50% less power consumption.
Original upper VX7000 board with useless analog TV tuner unit…
Modified upper VX7000 without analog tuner, no multilingual analog tuner, using satellite digital unit and can record it.
