TG 502/4 help needed

[ahlis_se]

Hello All,

first post here, I hope that my poor skills of the German language can be overseen by actually owning a Braun TG502/4 !
This particular one was inherited from my father but unfortunately some less skilled radio guys have tried to "fix" it.

These guys have manage to brake the VU- meter of which Im trying to locate a new one but so far I havent had any luck with this mission.

The transmission of the counter have broken also but this is due to plastic deterioration and Im looking for parts to this one too.

to put some icing on the cake I had a capacitor explosion to one of the engines ( marked "P3" ) so now all use of it have stopped, but I believe that I can replace the capacitor rather easy.





Do you guys know where I can find VU meters ( parts or complete new ones ) and parts for the counter mechanics ( or a complete one )

cheers for setting up this brilliant forum

[ahlis_se]

new capacitor fitted,

worked nicely for about 15 minutes then it slowly dropped tape speed.
I have purschased a service manual on ebay now and I´m about to make a list to replace all capacitors since I believe that this is the most probable cause of my issues with tape speed.

if you know what may be wrong please let me know.

brg
Erik

neue Kondensator ausgerüstet ,

funktionierte gut für etwa 15 Minuten dann fiel langsamer Bandgeschwindigkeit .
Ich habe eine Reparaturanleitung auf ebay jetzt purschased und ich bin dabei, eine Liste zu machen , um alle Kondensatoren zu ersetzen , da ich glaube, dass dies die wahrscheinlichste Ursache für meine Probleme mit der Bandgeschwindigkeit .

wenn Sie wissen, was falsch sein kann lass es mich wissen .

BRG
Erik

[ahlis_se]

Einige Bilder von meinem TG502/4















diesen "counter" sind kaputt

[ahlis_se]

Update:

Alle Elektrolytkondensatorenhaben nun zusammen mit den Elektromotor Kondensatoren ersetzt.
Mechanicly es läuft jetzt gut ist, ist es immer noch ein paar kleinere Probleme mit ihm aber.

Der Bremseingriffwird manchmal 5 Sekunden oder mehr verzögert. Ich denke, das hängt mit Oxid auf der Relaiskontaktflächen.

Es gibt schlechte Kontakt auf der Kanal-Schalter ( Spur 1,2,1 + 2,2 > 1,1 > 2) und die 2 / 2,2 / 4 -Schalter. Diese haben schlechte Aufnahme Ton verursacht, sondern wird immer besser , wie es erhält Reiniger.

Ich habe ein Problem der Aufnahme ist der linke Kanal viel empfindlicher als der rechte . bei der Aufnahme es scheint in Ordnung zu sein, 8 auf dem rechten Kanal , sondern gleichen Lautstärkepegel wird bereits auf 2. Ich weiß nicht, was ich zu diesem Thema zu tun erreicht werden.

alle Kondensatoren vor wurden ersetzt.



update:


all Electrolyte capacitors have now been replaced along with the electric engine capacitors.
Mechanicly it now runs good, it is still some minor issues with it however.

The brake engagement is sometimes delayed severly (5 seconds or more). I think this is related to oxide on the relay contact surfaces.

There is bad contact on the channel switch ( Spur 1,2,1+2,2>1,1>2 ) and the 2/2,2/4 switch. This have caused bad recording sound but is getting better as it is gets cleaner.

I have an issue recording, the left channel is far more sensitive than the right one. when recording it seems to be ok on 8 on the right channel but same volume level will be achieved already at 2. I don´t know what to do about this issue.

all the capacitors in front have been replaced.

[ahlis_se]

Ein bisschen Spaß Informationen .

Es gibt etwa 100 Kondensatoren und 32 Transistoren in der Braun TG 502-4 .

Es gibt noch weitere einstellbare Kondensatoren nicht gezählt ist.

[ahlis_se]

if there is any interest I can post the entire component list ( so far ) and what I have replaced it with.

[ahlis_se]

new issue found today.

If I measure between the chassi and ground I have 220 V AC ( I got zapped )
this cannot be right..
the player plays fine but still have issues with Spur 2, but I think I have located the circuitboard with possibly faulty transistors.

cheers

[ahlis_se]

I still have a very bad 50Hz humming in the second channel.
all transistors have been replaced on the first circuit board with the same issue.
If I disconnect the negative cable on the filter circuitboard it gests a lot better but channel 2 is still extremely sensitive.

I have cheated a bit about the 220 V AC power in the chassi of it. I have now added a ground lead to the player which greatly improved things.
The 220V current can be measured as soon as the player is plugged in even without switching it on. I have tried to find it and I suspect it to come from the capstan motor. I removed all power cables from the high power circuitboard and then it was gone. Maybe I need to replace that motor..

to be continued

[ahlis_se]

a tiny update. if anyone have any knowledge around this issue I can say that Im out of my league.
I have traced the input signal as follows:

ok orange circles are connections, green circles are replaced components. Incoming audio goes into pin 7 and 8, at the end of this channel you will find pin 13 and 14 going into the green cable hosing (containing black and green leads)


This is the next circuit board and this is a filter or an equalizer.
The black and green wires are connected to pin 32 and 33, again orange circles and the green components are replaced.

If I disconnect the pin 32 (the black wire) the 50 Hz nightmare bashing sound goes away, maybe just a faint humming in the background is there hard to tell without prober tools.



Again if anyone knows about anyone or knows anything about circuits like this one please help me as Im running out of Ideas.

Best regards

[ahlis_se]

Small update

Found a wiring issue, actually several. Smart money says that the humming is from a broken wire somewhere.

Will continue to chase for VU meter housings or still complete VU meters as I only have a broken one. Will try to get in contact with someone who does 3D printing to create new housings.

So if you have a housing or sticker with the silver bottom and black and red stripe or both. I am very _very_interested of buying those.

Please see my add here

Any help is much appreciated

Brg ahlis