Hi smart people's.

Could i please get some help identifying the circled components in the attached

Thanks

 

hi shippy,
Welcome to AAC.
Look at these PDF's for the LM293 and 106D.
The top left is a 4.7uF 20V cap.
E

 

Thanks Eric. Much appreciated

The blue circle really has me stumped though

 

hi,
It could be an on board LED, I can see some track going up to a 22oR resistor.???
E

EDIT:
Lift up the Red/Black wires so that we can see where the track runs.

 

the blue circled item from the first post in this thread goes into pin 10 of the max232, which is T2 IN ttl/cmos input ( the new photo is messy as the board is messy with hot glue , so i used the old pic)

Also the balc circled item? is that a blown resistor? it has 21.5k resitance but no continuity ? weird ?????


I really really appreciate your help. I have been chasing this issue for a very long time so i decided just to reverse engineer it, learn it, so i can trouble shoot it


see attached

 

The blue circled item could be a diode, a 1N4148 or similar?

 

hi s,
I misread the blue/black items in the first pic..duh!
The Blue circle component is a diode, I would say a 1N914 type.
The Black circle looks like an LED.
E

 

hahahah

cheers


Ill ask some more questions tomorrow...

 

The blue circled part is probably a 1N4148 diode. The wide yellow band serves as both the cathode marker and the first character of the part number using standard color codes (yellow = 4). The 1N4148 is probably the most popular signal diode in use, by a large margin. From most modern manufacturers, it is electrically identical to the 1N914.

The black circled part looks like a ceramic capacitor. "C0G" types are usually white. It is very rare to find a surface mount ceramic capacitor with any marking. Although they certainly exist, C0G types greater than a few tens of nanofarads aren't commonly used. They are more expensive than other ceramics so they usually are used only where their tighter tolerance and/or temperature stability makes them preferable. Of all the parts on the board, that one (assuming it really is a capacitor) is the one most likely to be damaged by hand soldering with an iron.

That board has to be one of the ugliest I've ever seen in terms of assembly. It has clearly been hand soldered, and very sloppily.

 

blue circle looked like a "flipped" resistor showing the white underside? to and from MAXxxx would be comm damping resistors on the Tx/Rx lines, like the 220 (22 ohm)shown mounted properly next to it

 

You guys are amazing, thanks so much

Attached is a mock up, (my first ever schematic lol) ill crunch all your info shortly and adjust the schematic accordingly

Cheers

 

blue circle looked like a "flipped" resistor showing the white underside? to and from MAXxxx would be comm damping resistors on the Tx/Rx lines, like the 220 (22 ohm)shown mounted properly next to it

Yup, I'll buy that argument. On close inspection it doesn't seem to have the wrap-around end caps that a capacitor would, and a flipped part would certainly be consistent with the general lack of care in assembly.

 

hahahah you guys are amazing

 

Yup, I'll buy that argument. On close inspection it doesn't seem to have the wrap-around end caps that a capacitor would, and a flipped part would certainly be consistent with the general lack of care in assembly.

All the hours of panels after panels one sees the oddities