[orava]

Also, you probably noticed that those wire connectors are terrible and cold loose connetion.

[orava]

What kind and from where did you find replacement belts?
I have one 1600 in my refurb cue.

[orava]

IF i remember right, I did have to change some transistor times ago… Maybe worth to check them?

[orava]

M75
S45
Penta

[orava]

Anyone (Chartz?) happend to know how MMCx000 series is build? Is it glued together  and is there a way to disassembe it?

[orava]

Went to PVA this time, have to buy new speaker glue with next surrondings.
Thank you for your opinion everybody

[orava]

Ok, Iám looking if there is something I can buy locally. I had Audiofriends glue but I ran out of it.

[orava]

With MMC6000 it could have CD4 decoder inside too. I have it in one of my 4002´s.

[orava]

They dont need to be snapped or loose, bad connection surface is all it needs.

[orava]

Probably needs full recaping, it has a lot of Rhodenstein red capasitors witch are bad by now. Also I had connection problems with wire wrap matrix where modules were plugged in.

[orava]

oh well, broken trace, things are not allways complicated…

Then mechanical adjutment and re-build

[orava]

Yes

and this is from 551x, so mine is 552x. (1IC1=TIP120)

[orava]

Well, I do not have any 0TR1, I C1 I guess..

As I say on first message newer board and service manual do not equal. Manual says “circuitry is basically identical” although layout and numbering is different. So I have to decode board with almost right circuit diagram.

[orava]

Reason for 4IC1 was bad aglinment.
For slow carriage movement shorted D31 between slow back 3V adjustment and motor feed transistors.
Next problem. Carriage motor wont stop at stop switch, and yes, switch is ok.

[orava]

Back on this for a moment…
On DVM transistors (TR19-22) on “ON” side base voltage is when “>” 5V an “>>” 14v but on “OFF” side (TR23-26) both “<” and “<<” app. 4V.

Also should 4IC1 collector be adjusted to 5V with R88, can adjust only to 6,5V min.

[orava]

Sorry all, I have talking rubbish (poor, poor memory).

You are absolutely right, >> is weak, and does NOT depend any other keys.

[orava]

Yes it is, but difference is do I press up/down before it.

[orava]

Hello

Mark, I mean if record is playing, I press arm up and then fast backwards, it does barely move as there is not enought voltage on motor. If press stop, arm goes to home position at normal speed.

Martin, I know, this board picture is from my “spare” machine, I do not know if it is even in working condition. Just so lazy I did not get actual board out of player.

I do like to check transistors but witch ones? Of ourse I can check them all but to know will ease process.

 

[Author]

Posts