So I started with the Power Supply PCB (6) and followed the instructions from - link . Sure enough 6c35 was at 1.8nf. Replaced the voltage regulator also. Measured 4.9v on output. So that looked good but the system still did not come out of standby.

Two observations -

1. Anytime I disconnect the main power, I can hear relays clicking (off I assume). Good sign ?

2, At one point while measuring power across 6c35, the system suddenly came alive for a second..with relays clicking and display panel lights coming on. And then silent again...Checked all the fuses, just in case something blew but all fuses were fine. Not sure if anything else blew.  (Yes, I have the Dim Bulb Tester on my to do list..I will complete that before switching on the system again).

Completed recap of Power Supply / Display / Microcomputer / Output Right. ESR meter showed 4 capacitors as damaged and majority of the capacitors were out of the tolerance values. There were couple which showed 5-6 times the original value.

After completing the right side, I moved to the left. 

I started with the filter and tone control pcb. Removed the PCB and first step was to replace the missing buttons that Martin had provided. When I removed the PCB which the buttons press on, I found my three missing buttons - they had come out of their slots and were stuck between the PCB and front panel). The reason they had come out was because the PCB itself had curved. So the three buttons in the middle came out. (I have seen Beomaster 8000 for parts and also panels on ebay that have those buttons missing and used to think the seller tried to fix and failed and lost the buttons - This misconception is now fixed).

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So the question is how do I fix the curve ? Without this the buttons wont work and will disappear again. 

Next I started with the Preamplifier PCB. I found two capacitors (C115/C215 - orange) whose value does not match with the manual. As per the manual they should be 10uf/63v but on the board they are 10uf/25v. I don't think the system has been repaired. Which one should I replace with ?

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I also noticed that some kind of lubricant has leaked from the damping system. (or someone tried to add it from the top or side). It is all over the left side. It's on the output pcb 5. 

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Notice the dust on the red connector on bottom right, there is no dust on the resistors below the damping system.(top right). It's all wet and shiny. Could this be the reason that system is not coming out of standby ? Fault-protection mode is activated ?

Any suggestions on cleanup process ?

I will be working on this board later this week.

1. Normal.

Replace connectors on CPU and display modules.
Redo the vias on the CPU board that Beolover also talks about.

Martin

Thanks Martin.

I will check the cpu board again.

I will come back to the connectors after the recap. 

Any guidance on the mismatch in capacitor values for 3C115 and 3C215 - 10uf 25v(on PCB) Vs 10uf 63v(manual) ?

Again, thank you for your guidance.

dahiyas wrote:

Any guidance on the mismatch in capacitor values for 3C115 and 3C215 - 10uf 25v(on PCB) Vs 10uf 63v(manual) ?

10uF 25V sounds best of the two. Perhaps one was replaced at some point.
Replace with tantals 10uF 25V or 10uF 35V.

Martin

Thanks Martin.

btw - So far I had just read about the incorrect polarity markings on the PCB's, This is the first time I have encountered them. Lot's of them. I have started marking polarity with a marker before pulling out the old caps.

So I completed the recap on all the boards this weekend.

Followed all of beolover's guidelines for different boards and Martin's advice regarding connectors. Cleaned (and Dexoit-ed) all connectors, reflowed solder. I still need to order new connectors. Checked all cables for continuity.

Nothing exciting except I had one capacitors polarity reversed (fixed) and I have the filter store button and balance button swapped (will swap later).

I didn't have the trimmers. Ordered last week and should show up on Monday. so next weekend will be used to replace those.

Some progress.

Good news is that the system now comes alive when input source is selected. Also, some segments on the source display are dead but others seem to be ok so not too bad I guess.

New challenge - The keys stop responding after a minute or so. see picture with vol 2 and fm freq indicator at 10. After this I have to pull out power and connect again and keys start responding again but again for sometime only. Haven't connected external source/speakers as yet.

Any guidance on what to look for ?

Thanks !!

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Couldn't stay away from the project 🙂

I pulled out the MP/Display board. Reseated all the cables again. Switched on and the system has been on for about 2 hrs. Keys are still responsive. Looks like loose connections but still doesn't explain the hang after couple of seconds.

So I was brave and connected external input and my headphones..and I heard music. so that's good news.

I found couple of new issues -

1. When I increase/decrease the volume, there is a clicking sound coming through with the audio..is that normal ?

2. The frequency tuning dial is not working. Turning it does not change the fm frequency. Could be the rotary sensors issue ? 

3. The display with the red covers (Clipping/Filters and Manual/Mono) indicators do not light up. I assume bad bulbs (6v/80mA) ?

Any inputs will be highly appreciated.

Meanwhile, I have started my search for right header pins/cables. Any recommendations ?

Thank you !!

Issue 1 - looks like I need to adjust the volume control DC offset trimmers (

Finally got some time to restart the project.

Source display is restored (finally). Replacing the SMD LEDs requires a lot of patience. Ended up buying a cheap digital microscope and that really helped the process. I am not going to touch the other displays right now and come back to them at a later date. 

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