The PCB on a Shernbao dog grooming dryer has an unmarked 8-pin IC (see pinout below). This PCB controls the blower motor speed with a BTA-26 triac. Can someone help me identify this IC?

 

Can you post a picture of the circuit and chip in question?

 

Can you post a picture of the circuit and chip in question?

How about this?

 

It could be an 8-pin Microchip PIC MCU.

Edit: I take that back. The PICs I am looking at have VDD on pin-1 and Vss on pin-8.

 

How about this?
View attachment 342384

Here's a picture of the actual PCB.

 

Hi,
Why do you suspect the I.C,
I can see there is not a lot of suspects.
Is the motor OK?

 

Hi,
Why do you suspect the I.C,
I can see there is not a lot of suspects.
Is the motor OK?

Motors(two) are fine. Diodes are good by a multimeter as is the external triac. No voltage across the 5-volt zener diode when powered up. That makes me suspect the IC.

 

It appears the part of the schematic that is not shown is a "transformerless capacitor power supply". It looks something like this. The values are different. It is also likely that something in the power supply failed. In the schematic below the first resistor on the left (10 to 500 ohms) is also used as a fuse.

 

I agree with Ron; most likely one of the PS components failed.
I have personally seen open-circuit film caps, although most likely the series resistor could also be a fusible type which opened up.
Time to troubleshoot with your DMM

 

Yes. The actual circuit appears to be a "transformerless power supply" with a slightly different arrangement of the 1N4007.

All resistors are intact. Not sure about the electrolytic capacitor. I will have to take a more in-depth look at the circuitry. I may have jumped to a conclusion in my initial analysis.

Thanks for the responses to my post. Much obliged.

 

Electrolytic capacitors are always a prime suspect.