Laney LA65C, TDA7294

[Lopo1132]

Hello, I have a guitar amp Laney LA65C where the output amp is faulty, it consists of a TDA7294 IC, I put in a new TDA7294 but it exploded as soon as the power was turned on. I checked the input voltage and it is correct 26 volts, what could cause it to explode, are there several versions of the TDA7294 with other supply voltages? There is no insulation between the circuit and the heat sink, but the heat sink has no contact with the device body.

[AScha.3]

Hi,

>are there several versions of the TDA7294 with other supply voltages?

No.

Just H or V (vertical mounting, see ds.)

+

>input voltage and it is correct 26 volts

?? chip has +/- supply, so check it, before putting in the next victim.

+

>There is no insulation between the circuit and the heat sink

Check, if there is any connection heat sink to circuit or gnd ! Tab is on -Vs , neg. supply !

[Peter BENSCH · Accepted solution]

Welcome @Lopo1132, to the community!

You asked the same question in the music-electronics-forum. The thread there already mentioned possible problems with the power supply - did you check it thoroughly before installing the replacement, i.e. the voltages on pins 7, 13 and 8, 15, as Jazz P Bass suggested?

In addition, when buying on eBay, you have neither a guarantee of function nor guarantee of an genuine component. It would be better to buy it from our online store:

• TDA7294V (vertically mounted)
• TDA7294HS (horizontally mounted)

You'll also find the differences in the data sheet of the TDA7294.

Regards
/Peter