A2098 Transistor Reads OL on a Multimeter: Is That Normal?
- By Ellen Joy
- On Sep 29, 2026
- Comment 0
Question: I tested the A2098 transistors I received with my multimeter, and they all read OL. Is that normal?
Answer:
An OL reading means the meter does not detect conduction in that probe arrangement. It is normal for some A2098 transistor measurements, but a transistor that reads OL in every direction across every pair of legs needs a closer check.
First, confirm that the marking is A2098, also designated 2SA2098, and set the multimeter to diode-test mode, rather than continuity mode. The Sanyo 2SA2098/2SC5887 datasheet [https://datasheet4u.com/pdf-down/2/S/C/2SC5887_SanyoSemiconDevice.pdf] identifies the 2SA2098 as a PNP transistor. With its printed face toward you and its legs pointing down, the legs are base, collector, emitter, from left to right. The same datasheet covers the 2SC5887, which is an NPN part; the probe directions below apply specifically to the 2SA2098.
Unplug the printer before handling its electronics. For the most reliable reading, test a transistor removed from the circuit board: connected components can change an in-circuit reading. Let the board's capacitors discharge, and do not touch exposed power-supply circuitry.
| Red probe | Black probe | Expected basic diode-test result |
|---|---|---|
| Right leg, emitter | Left leg, base | A forward-voltage reading, often around 0.45-0.8 V |
| Middle leg, collector | Left leg, base | A forward-voltage reading, often around 0.45-0.8 V |
| Left leg, base | Right leg, emitter | OL |
| Left leg, base | Middle leg, collector | OL |
| Middle leg, collector | Right leg, emitter | Usually OL |
| Right leg, emitter | Middle leg, collector | Usually OL |
The key check is to put the black probe on the left leg (base) and touch the red probe to each of the other two legs, one at a time. A good PNP transistor should normally show a forward reading for both of those checks. Reversing the probes should normally produce OL.
If you still get OL for both base-to-emitter and base-to-collector checks in both directions on a removed transistor, an open junction is possible. Before concluding that all the supplied parts are defective, verify that the probes are fully plugged into the correct meter sockets, confirm diode-test mode, and check the meter against a known working diode. A reading near zero in both directions across a pair of legs can instead indicate a short. Passing these basic checks does not guarantee that a transistor will work correctly under load.
Please send a clear photo of the markings on one transistor, a photo of the meter showing its setting and probe connections, and the readings you get with the black probe on the base and the red probe on the collector and emitter. Those details will help us confirm the part and test method before assessing the transistors.
Printer problems can be difficult to diagnose from a distance because many checks require hands-on inspection. We cannot provide remote troubleshooting or repair support, but we offer in-person evaluation through our printer repair service [https://bchtechnologies.com/printer-repair-service]. The service operates on a first-come, first-served basis, and there may be a wait of several weeks before a printer can be dropped off. We can evaluate a complete printer or specific parts; the service page explains how to proceed. We also recognize that professional repair may not be the most economical choice, so online research is a good place to start. On the BCH Technologies YouTube channel [https://youtube.com/@bchtechnologies], use the search icon near "About" to look for your particular model or symptom. We've published videos over many years, and searching is the quickest way to find a relevant one; YouTube may also show helpful videos from other creators.
Thank you again for taking the time to check the transistors and for supporting BCH Technologies.