Schematic for Marantz PM55-SE

[KevinAB]

Hi can anyone point me in the right direction.
My recent purchase off Ebay, a Marantz PM55-SE amplifier, seems to have been used as a football by the Post Office.
The facias is caved in and when I went to switch it on it started smoking and glowing!
I know absolutely nothing about electronics but thought attempting a repair would be a good place to begin learning. The amplifier didn't cost a lot.
I guess the first thing I need is a schematic - not that I understand how to read them but you have to start somewhere!

[Ian Finch]

A schematic is sure a good idea for repairing but have you assessed the internal damage?
If the circuit boards are cracked or leads and copper foil torn, controls broken, power supply
damaged etc. you need to think what expertise will be needed to fix a mess like that.
You may have to cut your losses and consider becoming a DIY builder rather than fixit.

[Ian Finch]

Sorry Kevin AB, I should have added that you can download PM55 manuals for free at HiFiengine. Google it and you can search easily.

[KevinAB]

Originally Posted by Ian Finch

A schematic is sure a good idea for repairing but have you assessed the internal damage?
If the circuit boards are cracked or leads and copper foil torn, controls broken, power supply
damaged etc. you need to think what expertise will be needed to fix a mess like that.
You may have to cut your losses and consider becoming a DIY builder rather than fixit.

Thanks for the quick reply. Apart from the cracked facia panel, there doesn't appear to be any immediate signs of damage - at least to my untrained eye! I have no doubt that I've probably set myself a task which is going to prove to be way beyond my understanding and capabilities. I need an idiots guide to electronics

I've just swapped over the fuse and turned it on with the cover off. There's a componet which glows. Right now I do not have a clue what it's called or what it's meant to do! It's white, about 1" x 1/2" (no idea what that is in metric) and has an inscription 3w 0.80R x 2 (that may not be correct as my eyesight ain't what it used to be either ) but there is an identical one on the other side of the board.

Thanks for the link to the schematic. I'll have a shufty now and see what sense if any I can make of it.

[Ian Finch]

Beware the model is not PM55 SE. There will be differences. It seems from posts that the SE version service manual is not freely available.

I cannot locate the power resistors you described. Can you read the part number or its twin part number from the print on the board? If these do not match anything, then the manual may be near to useless for you.

[KatieandDad]

I haven't got the schematics but power resistors are usually around the output transistors or power supply.

This could be a MAJOR learning experience for a newbie.

[KatieandDad]

Originally Posted by Ian Finch

Beware the model is not PM55 SE. There will be differences. It seems from posts that the SE version service manual is not freely available.

I cannot locate the power resistors you described. Can you read the part number or its twin part number from the print on the board? If these do not match anything, then the manual may be near to useless for you.

How much difference is there between the PM55 and the PM55-SE ?

I would have thought that they would be similar enough for an experienced engineer to work between the two.

Philips always used to promote the Marantx SE's as just Special Editions, then there were the SE Gold versions.

[KatieandDad]

If it was working and now its been physically damaged, I would certainly suspect the solder joints around the amp.

Do a search on DRY-JOINTS to get an idea of what you should be looking for. Unlikely that you will have dry joints but you will almopst certainly have broken joints.

[sasha70]

Hi, send it back and ask seller to claim damage from the Post Office, hope he has paid insurance. I have done same with damaged speakers I have bought on e-bay on the past.
Regards.

[KatieandDad]

I did the same with an Oscillocope. Royal Mail eventually replaced a 'scope that they ruined in the post. It all depends on the Insurance that you paid.