Electronics Forum / Electronics / July 2008

I was afraid to read that :-). Probably I would be able to fill earths
biggest hole for free with CRT-devices, would I only come by to
take them.

Did you play a bit with their site?
http://www.blaupunkt.com/html/index.htm

This is a global phenomenon. The gadgets are baked, packed
and said good-bye to. Customers? Drop dead after having paid.

Anyhow, good luck and
regards,
H.

You won't get lucky trying to get technical assistance from Grundig on
sets that old. The former Grundig company of Fuerth, Germany has been
bankrupt and the name - not the knowledge and quality of service/
design - sold some years ago. What nowadays goes by the name "Grundig"
is not worth the bandwith wasted writing about it. And Blaupunkt
dropped out of the TV segment almost decades ago, after all they
mostly rebadged Grundig Chassis. So there is no use trying to get any
info from either of them.

What you have there is some fine machine from the good old days, and I
am really sorry I have no info on that particular IF module, since
I've never seen AUS sets. The 29504-102 PAL BG IF Module with german
type 5.5/5.74MHz Subcarrier (Not NICAM) Stereo decoding based on
TDA6611-2 is depicted in the CUC5510/11 schematic (DL-able on
eserviceinfo). Maybe this will help some.

Unfortunately this set does not have the well known washer contact at
the mains switch that regularly caused audio mute problems in earlier
Grundig models. So it's other problems you will have to look into.

With CUC6330 you may try this:
Since the IF Module is not the same as in the German models I know,
get the Datasheet for TDA6612-5 from alldatasheet.com and see if you
can scope something on the input of this IC the way it is coming from
the U2840 - so you rule out the U2840.
Try Scart AV.
Generally with any of these sets scope the I2C at the TDA6612 to see
if a level of 5V is reached when the SDA SCL line is being released,
and the edges on the Hi-Lo Lo-Hi transitions are not too sloped.

The test I used for IC like TDA66xx/6200/TY45018 etc used in Grundigs
and similar sets whenever swaping the module was not an option, is to
take the chip off the bus and attach a I2C monitoring/control software
like IICUNI.EXE with its simple hardware interface to the chip and see
if the chip does respond to the address probe command of the software.
I found most of the time one of these chips are gone (mostly due to
arcover from tripler/DST), they are gone for good and won't even
respond to their address being called.

BTW Since TDA6612 controls the volume and source selection like
TDA6611, I suspect it to mute the sound unless it is initialized via
I2C,- just like the TDA6611 and TY45018 etc generally do. So I
wouldn't expect taking the TDA6612 off the BUS would do any good
unless you init it manually via some dongle/software using the
commands from the datasheet.

Sadly as with most of these models the spare part plus labor is mostly
beyond the limit of most customers.

-regards, Robert

It's SAL Electronics:
http://www.salelectronics.com.au/service.html

BTW, the TFK IC was a U2860B, not a U2840B. Sorry.

- Franc Zabkar