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Olivetti collection
- Thread starter fedefede
- Start date
Ruud
Veteran Member
Where do you live?
Hello
I have got a m300-04, but due to capacitor plague (and me not cheking before turning on), the power blew up and one chip also did.
@fedefede do you have hi res pictures of the power board by chance? I cannot read the reference of the chip on mine anymore, and need to change it.
Thanks in advance
JC
I have got a m300-04, but due to capacitor plague (and me not cheking before turning on), the power blew up and one chip also did.
@fedefede do you have hi res pictures of the power board by chance? I cannot read the reference of the chip on mine anymore, and need to change it.
Thanks in advance
JC
Dwight Elvey
Veteran Member
What no M20?
In my list these isn’t m20
Hello
Thanks @fedefede!!!
Here is a picture of my power board, the chip circled in red has blown up and I cannot read its reference
If I could get a good picture I would be able to fix this old chap
(at least if I can find a replacement, but this will be another story!)
Thanks in advance!
Thanks @fedefede!!!
Here is a picture of my power board, the chip circled in red has blown up and I cannot read its reference
If I could get a good picture I would be able to fix this old chap
(at least if I can find a replacement, but this will be another story!)
Thanks in advance!
Last edited:
This is a set of pictures of a full recap I made
years ago on a Olivetti 286, original caps were
fully rotten ...
This power supply is used in several machines.
The switcher should be this :
years ago on a Olivetti 286, original caps were
fully rotten ...
This power supply is used in several machines.
The switcher should be this :
TEA2018A Datasheet(PDF) - STMicroelectronics
CURRENT MODE SWITCHING POWER SUPPLY CONTROL CIRCUIT, TEA2018A Datasheet
www.alldatasheet.com
Attachments
Since the fuse is blown, be aware that most likely
you have more damage on the primary side other
than the switcher IC. I can see a dark spot on R8 too.
I would check thoroughly any component on the primary side,
especially semiconductors. TR1 is probably shorted.
you have more damage on the primary side other
than the switcher IC. I can see a dark spot on R8 too.
I would check thoroughly any component on the primary side,
especially semiconductors. TR1 is probably shorted.
To test diodes and transistor use a multimeter in diode mode
(plenty of YT videos ...).
This is a link to the swicther IC datasheet :
at page 6 there's a schematic with a typical application.
R8 could be a low value resistor that acts like a
current sensor for the chip and it's connected in series
to the emitter of TR1.
The same current that caused R8 to burn should have
caused TR1 to short.
Of course real schematic could be different.
(plenty of YT videos ...).
This is a link to the swicther IC datasheet :
at page 6 there's a schematic with a typical application.
R8 could be a low value resistor that acts like a
current sensor for the chip and it's connected in series
to the emitter of TR1.
The same current that caused R8 to burn should have
caused TR1 to short.
Of course real schematic could be different.
thanks again. I will test TR1 with a multimeter (and while I'm at it other transistors and diodes) and if it is shorted then order parts to replace them. I should open a thread here and ask the moderators to move the messages there for the posterity (well, if someone needs pictures of this board).