BOB4 installed backwards

[br1507fe]

I was in a hurry and got BOB4 reversed.
When I applied USB power the SS14 diode on BOB2 got quite hot.
Are either BOB2 or BOB4 likely damaged?
What other parts might have gotten fried?

[jye1]

It's hard to tell which part was damaged. Sometimes parts may just got hot but not damaged or not fully damaged. You can try again after making sure polarity is correct. Just be ready to cut power supply when you find something hot.

[br1507fe]

I think I might have fried the processors, is it possible to get programmed replacements for the 48pa and the 64a?

[jye1]

USB power is 5V so it shouldn't damage M64 or M48, both of which are 5V tolerance. Likely BOB4 has been damaged. But you can try even without BOB4. Close JP1, JP2, and JP3. Connect to USB and see if the scope works. As precaution do not close JP4. Check voltage at +5V test point (TP23)first. If it is good disconnect power. Close JP4 and check the resistance between +5V and GND to make sure no shorts. Then apply power again. In this case you may see voltage at +5V test point only 4V something. But the scope can run at this voltage with some display error though.

[br1507fe]

Thank you for the instructions.
Results as follows:
Opened jp4, closed jp1-JP2-jp3.
By tp 23 I assume you mean +5 just above D3
Connected UCB power source, +5 tp = 4.9v
Disconnected UCB power source
Closed jp4
Measured Resistance between +5 and ground > 500 ohm.
Connected UCB power source
Measured +5 tp was about 4.6 v.
D1 did not blink, verified flat side of D1 is on the C32 side, and bp1 has + towards outside of board.
Any further testing I can do?

PS I like the idea of this scope, so I purchased another kit to build. Put it together tonight and performed 1st power tests successfully.

PPS installed SW1, set it to GND ( towards center of board ) and took voltage measurements.( UCB power source, no battery) same conditions as above Jp 1,2,3,4 closed.
Vbus = 4.97
+5 = 4.6
-5 = -4.99
V5 = 3
AV+ = 4.6
AV- = -4.9
V3 = 0
V2 = 0
V4 = 1.6
VB = 0.55
VT = 2.4
V1 = 0
VA = 4.5
VEE = 4.58
Sysclk = 2.26
M64 pin 20 = 4.05
Vbat = 4.17

[jye1]

The voltages look ok. Without BOB4 voltage at +5V test point will be less the 5 due to drop on D4.

[br1507fe]

What information can be obtained on the health of the m48 and the m64 using ISP?
I have programmed a little with PIC processors, but have no experience with these.

[jye1]

If you have an AVR programmer you can try to re-flash the MCU's with codes available at http://www.jyetech.com/Products/LcdScop ... es_068.php. For AVR MCU's the fuse bits need to be programmed properly. The information about fuse bit settings of DSO068 is contained in the User Manual. Please see http://www.jyetech.com/Products/LcdScop ... al_068.pdf

[br1507fe]

Is it possible to get a BOB4 board by itself?
Or can you give me a cross reference for the IC that is on the BOB4 board?
Thank you.

[br1507fe]

I would like to add that I'm not finding a small quantity source for the QX3400