In this guide, we explore the diagnosis and repair of an industrial electronics board from an oil pump controller. The question is: Can we repair these kinds of devices using general electronics knowledge? The answer is yes — if done carefully and logically.
In the past, I’ve been doing industrial electronic repairs for about 4 years, mainly CNC machines, it’s always a pleasure every time I have a job coming from this sector. I uploaded on Youtube a video fixing a control board from an industrial device, but those kinds of videos are very hard to be digested by a regular viewer. Industrial Electronics is a different kind of monster, there is no place for mistakes as the boards are not only expensive, but you can’t even find them to buy or even if you find them, they need to be programmed by the manufacturer. The board from the video is over 1000$, the precision of a repair like that, should be unmatched with any other repairs. Indeed, they are paid very well, but the time spent for diagnosis & repair is 10 times more than any other kind of repairs, because, like I said, there is no place for mistakes!
🔧 Job Summary
- Device: Unknown industrial electronic board (likely oil pump related)
- Reported Fault: Board intermittently stops working, clicking the relays brings it back temporarily
- Observation: Industrial electronics = high value repairs
These jobs can’t be solved by watching a generic YouTube repair video. They require real diagnostic skills.
🤍 Step 1: Visual Inspection
- Removed the board and inspected for cracked solder joints, especially near relays and MOSFETs
- No visible damage or cracked joints found
🔢 Step 2: Relay and Coil Testing
- Board had 3 relays, each with 4 pins
- Checked relay coils and associated diodes using a multimeter
- Identified relay coil resistance around 700 ohms
- Verified one side of coil was tied to ground, other went to a MOSFET or control circuit
⚡ Step 3: Activating Relays Safely
- Applied 12V with very low current directly to relay circuits
- Verified relays click and associated LEDs light up
- Confirmed correct switching via continuity test
⚠️ Important Note:
Relays may click under test, but fail under real load (e.g., 40A). Only full-load testing can truly verify relay integrity.
🤷 Step 4: Identify Inconsistent Behavior
- Intermittent relay behavior found:
- Continuity sometimes present, sometimes not
- Resistance across relay contacts varied widely (from 1.4 ohms to 14 ohms!)
🚨 Conclusion:
- One relay was clearly faulty
- This explained the original customer complaint: board starts working after tapping
🛠️ Final Thoughts: To Repair or Replace?
- Best solution: Replace the faulty relay with same-spec component (12V, 40A)
- Temporary options (not recommended):
- Reflow or resolder relay pins
- Swap relay from unused channel (if available)
- Open and clean relay contacts (unreliable)
💡 Takeaways for Industrial Repairs
- General electronics knowledge can be enough to troubleshoot industrial boards
- Proceed logically: identify relays, trace paths, use safe voltage testing
- Never guess. Understand what each component does and why it may fail
- Avoid “dodgy” fixes unless you can monitor and support the customer post-repair
Industrial customers rely on stability. Your repair must last years, not days.
📹 Watch the full repair on YouTube:
Industrial Electronic Repairs – Can We Do It with General Electronics Knowledge?
https://www.youtube.com/watch?v=dj7_nxVtnaE
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