Hantek DS05102P Channel deaf - 4 pin chip fail?

[Geesaw]

I'm so old I remember that you should always say hi in forums, do people still do that? I feel I should. My name is Gary, I'm fast approaching 60 and have bought a Rigol OScope which is a constant source of education. I live in Essex in the UK and have always liked basic electronics and mechanical fettling. I am owned by a wife, two kids and two cats, in that order.

A friend gave me a  Hantek DSO5102P to look at with a dead channel. I  put a sine wave on the input and used the Rigol to check the signal back through the circuit. It didn't get far as it didn't get past a four pin SMT Chip marked M 280 7336Q which seemed to be right behind the BNC socket, the first component. The other channel is fine and I used that to compare signals.

Q- I can't find any reference to this chip, any ideas? If you do know, how did you find out?

I have tried a blog search but can't find anything on this chip/package directly. Feel free to advise if I've done something silly, I'm on a journey and always try to take on advice. T.I.A.

Gary

[mikerj]

Welcome to EEVBLOG!

That part is likely a AQY280S opto "relay", effectively a couple of back to back MOSFETS with the gate drive coming from an LED.

[BreakingOhmsLaw]

I'm so old I remember that you should always say hi in forums, do people still do that? I feel I should.

Well, I'm old enough to appreciate that. So welcome!

Here's a tip: When asking to identify components, providing images increases the chance of success significantly. You can use the forum image functions or use site like imgbb  to host images that you can include in your posts.
Images can give us additional hints to narrow it down like the package type, manufacturer logos, etc.
I never cease to be surprised how often the EEV forum hivemind can identify obscure parts.

Again, welcome and let's fix stuff instead of feeding the landfills.

[Geesaw]

Thank you. That is pretty much spot on but for the last four numbers, my image would be exactly that, you have me back on the road, and that's pretty cool  Kudos.

[Geesaw]

Cheers! Now you have said it, it makes perfect sense. fixing stuff is right up my Street, appreciate the welcome and I have an answer already! What a forum 

[Geesaw]

Just a quick update, opto relay replaced but still deaf so went on to find a SMD Resistor of 20 Ohms that had obviously expired as it passed no signal, I also noted while the working channel equivalent was marked 30X, the failed one was just a really dark black, like not emitting any light at all. I assume the magic smoke has been let out and the resistor is devoid of anything, like a little black hole of electronics. I was tempted to short it but I've ordered a few resistors and will attempt to put it in when they arrive. If I don't sneeze and blow it away somewhere.

[Adrian_Arg.]

welcome to the Seesaw forum, I inadvertently blew out various components with a single station heat gun, and I continue to do so.